With rapid development of a current network, many conventional services have been transferred to a network environment for implementation. Due to vulnerability of the network environment, a server often needs to be maintained, thereby interrupting a user service. An existing high availability cluster server system includes at least two server nodes, and implements uninterrupted running for a long time through switching between a main server and a standby server.
During the implementation of the foregoing technical solution, the inventor finds that the prior art has at least the following problems: due to a limitation of a method for switching a user link, when an application program running on the main server is transferred to the standby server, the application program must be re-started on the standby server, so as to continue to provide external services. In a case in which the application program on the main server is closed, a communications link established between a client and the main server is disconnected, and at this time, a user may perceive interruption of the service. In addition, a data packet being transmitted between the client and the main server may be lost, thereby bringing great inconvenience to use of the user.